A bit error rate (BER) is the conventional metric used to analyze communications systems using probability theory. A conventional BER counter counts the total number of errors per a number of bits sent. Error correction is often performed on a received bitstream. Forward error correction (FEC) is an error correction technique to enable correcting some bits transmitted in a bitstream. Existing techniques to estimate post-FEC BER rely upon obtaining the pre-FEC BER of the received test pattern and apply a statistically estimated number of correctable errors to get the post-FEC BER estimate. Because any number of errors in an m-bit symbol is considered just one error, this technique results in the number of correctable symbol errors in a codeword being highly dependent on the distribution of errors in the received test pattern. The number of symbol errors will affect if a codeword is entirely discarded and hence affect the eventual BER. As the error distribution is dependent on the channel, a method to statistically calculate the post-FEC BER may not be reliable for all channels. A current method is to statistically estimate the post-FEC BER based on the raw BER, which is not accurate because the post-FEC BER can vary significantly depending on the channel.
Accordingly, circuits and methods that generate error spacing information associated with an input stream are beneficial.